Some ambient light detectors are used to reduce overall display-system power consumption, e.g., for energy saving displays, by detecting ambient light conditions as a means of controlling display and/or keypad backlighting.
In order to achieve better ambient light sensing, it is desirable for the ambient light detectors to have a spectral response close to a human eye response. Because the human eye does not detect Infrared (IR) light starting at about 750 nm, good noise suppression from the non-visible light, such as (IR), is desirable.